Gas turbine engines typically include a compressor, a combustor, and a turbine, with an annular flow path extending axially through each. Initially, air flows through the compressor where it is compressed or pressurized. The combustor then mixes and ignites the compressed air with fuel, generating hot combustion gases. These hot combustion gases are then directed from the combustor to the turbine where power is extracted from the hot gases by causing blades of the turbine to rotate.
Various components of the gas turbine engine, such as fan, compressor, and turbine airfoils, are subject to high tensile and vibratory stress fields due to the high rotational speeds of the gas turbine engine rotors. Airfoil damage, such as cracking, or failure may result from high cycle fatigue (HCF) caused by the induced vibratory stress cycles. In addition, modern engine design trends have incorporated higher rotor speeds, higher stage pressure ratios, and reduced axial spacing; factors which all increase the strength of the disturbances exciting the engine components. Therefore, it is necessary to address HCF risk during design and validation of the various engine components.
Currently, design and validation practices to mitigate HCF risk are predominantly deterministic, single-point assessments that do not explicitly capture the inherent blade-to-blade and engine-to-engine variability in HCF behavior. Accordingly, there exists a need for HCF design, analysis, and validation techniques that recognize the inherent variability in manufactured components and usage of gas turbine engines.